Alto II display control circuit board
There is a manual switch with the following printed on the switch: "EXT" on top of switch "INT" on bottom of switch.
Xerox PARC (Palo Alto Research Center)
||Silk screened on component side of board.
||Labeled as "PWB NO." This number is silk screened on component side
||Ink stamped on wiring side
||Labeled as "ASSY NO." The numbers are silk screened and the "E" is ink stamped
overall: 1/2 in x 11 in x 7 3/8 in